Firestore CRUD operations in React Native - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does CRUD stand for in Firestore operations?

CRUD stands for Create, Read, Update, and Delete. These are the four basic operations to manage data in Firestore.

beginner

How do you add a new document to a Firestore collection in React Native?

Use the add() method on a collection reference. For example: firestore().collection('users').add({name: 'Anna'}) adds a new user document.

beginner

Which Firestore method is used to get a single document by its ID?

Use doc(id).get() on a collection reference. For example: firestore().collection('users').doc('abc123').get() fetches the document with ID 'abc123'.

intermediate

How do you update fields in an existing Firestore document?

Use the update() method on a document reference. For example: firestore().collection('users').doc('abc123').update({age: 30}) updates the age field.

intermediate

What happens if you use set() with {merge: true} in Firestore?

It updates the document by merging new fields with existing ones without overwriting the whole document.

Which Firestore method adds a new document with an auto-generated ID?

A add()

B set()

C update()

D get()

The add() method adds a new document with a unique ID automatically generated by Firestore.

How do you delete a document in Firestore using React Native?

A collection().delete()

B update({deleted: true})

C doc(id).remove()

D doc(id).delete()

Use doc(id).delete() to remove a specific document by its ID.

What does get() return when called on a document reference?

A An array of documents

B A promise resolving to the document snapshot

C The document data directly

D Nothing

get() returns a promise that resolves to a document snapshot, which contains the data and metadata.

Which method overwrites the entire document in Firestore?

A update()

B get()

C set() without merge option

D add()

set() without {merge: true} replaces the whole document content.

To read all documents in a collection, which method is used?

A collection().get()

B doc().get()

C add()

D update()

collection().get() fetches all documents in that collection.

Explain how to perform each CRUD operation in Firestore using React Native.

Think about the Firestore methods for collections and documents.

Describe the difference between set() with and without the merge option in Firestore.

Consider what happens to existing data in the document.